More of a JS question than an Ext question:

Let's say my Ext app, eg. .js file size, is normally 100K all-in. But sometimes I want to bring up a complex panel (window, tab, etc.) that contains another 200K (.js file size) of code, and once I'm done, typically a minute or two later, I want to free up any resources that I was using, on the assumption that I am never going to do that again.

How does this work? I am guessing I should set any variables to 'null', but what about the fact that that (second, larger) .js file gets loaded into my browser via the text/script tags? Is there any way to 'unload' this? Does this question make sense?